With age a large portion of the population develops arterial obstructions formed by fats, fibrous material and calcified deposits, resulting in a diminished blood circulation. These obstructions can induce blood clots which further diminish or block the blood flow. When this occurs in the coronary arteries serving the heart muscles it is referred to as a heart attack. Presently such obstructions are bypassed with a graft or they are treated by angioplasty using a catheter equipped with a balloon which is inserted, over a flexible guide-wire, into the obstruction through the arterial system and then inflated to dilate the obstruction's lumen. Problems with this treatment are that it injures the arterial wall and may burst it. In certain cases it is ineffective. It creates a rough lumen. It does not remove the obstructing material out of the vascular system and may even release obstruction material into the vascular system. Thus, angioplasty during a heart attack carries the risk of dislodging particles of the blood clot and allowing it to move down stream creating further, potentially critical, damage.
An objective of the present invention is to provide a flexible torque transmitting rotary-catheter for an atherectomy system which can be percutaneously or intra-operatively introduced into the vascular system for cutting and removing an obstruction therein. The flexible rotary-catheter is insertable and rotatable over a flexible guide-wire and transmits rotation and torque to rotary coring means at its distal end from a motor affixed to its proximal end.
A further objective of the present invention is to provide a flexible rotary-catheter that would positively remove out of the human body the obstruction material, including blood clots if present, create a smooth lumen, and would minimize injury to the blood vessel's wall.
A further objective of the invention is to provide a system that can be used during a heart attack to provide an immediate relief and a long term correction of the diseased arterial site.
The flexible rotary-catheter should lend itself to be producable in diameters down to around 1mm (millimeter) and a length of around a meter to be able to reach and enter small and remote blood vessels. Preferably, the procedure using the atherectomy system would resemble angioplasty so that present skills of the medical staff can be utilized.
The flexible rotary-catheter should be simultaneously flexible and capable of transmitting torque so that when it is introduced percutaneously to treat an obstruction in a remote artery, for example a coronary artery, it can assume a tortuous path of the vascular system including some sharp turns found in the coronary vascular system.
These and other objectives of the invention will become apparent from the following discussion and the accompanying drawings.